The building will act as a symbol for a 1.5bn-square-foot "global city" - as dense as Manhattan - built on an artificial island off the coast of Dubai. Waterfront City, which will shield the existing Palm Island, promises to be home to 1.5 million inhabitants - effectively doubling Dubai's population - and create one million jobs.

The city, moreover, will contain a logical grid of 7x7 streets that should ensure that the "city [will be] on a human scale ensuring not only the ease of traffic passing through the city but also creating walkable distances between blocks". The sphere itself, with a telltale circular recess that looks like its been taken from George Lucas's drawing board, is conceived as a self-contained three-dimensional urban neighbourhood and will encase various public institutions in a series of smaller spheres suspended on the inside and connected by escalators enclosed in long tubes.

The idea of a ball shaped skyscraper has been kicked around by OMA before, but will Waterfront City finally mark its realisation? Or has Koolhaas got something more sinister on his mind?